Kris, 28, – who won season eight of American Idol – shared a photo via Instagram of himself in hospital gear.

He wrote: “My outfit for the day. The best outfit ill ever where. #bestdayofmylife”

The couple were high school sweethearts and were married in September 2008 – just months before he auditioned for American Idol.

US Weekly reports he said at the SXSW Festival in Austin, “I am really excited. I’ve always wanted to be a dad…[Katy has] already started buying him clothes like mine. He’s already got some [fedoras].”